INDIANAPOLIS (AP) — The voter registration surge in Indiana this year has caused a peculiarity — some of the state’s counties have more names on their voter rolls than the number of adults who live there.

Election officials attribute that to thousands of people listed as “inactive voters” who have likely moved away but have not been dropped from the registration lists.

The issue has drawn attention in recent days with postings on political blogs about the apparent excessive number of voters registered in Marion County, which includes Indianapolis and is the state’s most populous. The county also is considered a strong base of support for Democratic presidential candidate Barack Obama as he tries to win Indiana’s electoral votes over Republican John McCain in the Nov. 4 election.

State records show that as of Friday the county had 682,016 registered voters, while the most recent U.S. Census estimates are that the county had about 645,000 residents 18 or older in 2007.

Marion County’s figures include about 118,000 inactive voters — those who in many cases have moved without notifying election officials.

A county election official and Indiana Secretary of State Todd Rokita disagree on whether perhaps more than 80,000 of those names should have been removed from the voter rolls, but Rokita makes no allegations of fraud in Marion County.

“I believe it’s an issue of sloppiness rather than anything intentional in terms of deceit,” said Rokita, a Republican who is the state’s top elections official.

John Riordan, the Democratic member of the Marion County voter registration board, said thousands of names would probably be removed from the list next year. Those who could be removed are those who don’t vote in a second consecutive federal election after unsuccessful attempts to contact them by mail in 2006.

“Had we removed the inactive voters on the rolls prior to this election, we would have violated federal law,” Riordan said. “Anybody who is going to vote in Marion County is going to vote this election. So after this election, we will have a very good idea of who the actual voters in the county are.”

Spot checks by The Associated Press among Indiana’s 92 counties found some others with over-registrations similar to Marion County.

Those include Orange County — with 15,982 registrations and an estimated 14,800 adults — and Jennings County — 22,044 registrations and about 20,500 adults — in southern Indiana and northern Indiana’s Grant County — 53,509 registrations and about 53,100 adults.

Rokita said he had not looked into the situations in other counties. He said all counties should be using a statewide voter registration database to identify those who have moved and registered in other counties or have died.

“I do think that Marion County and maybe some other counties are not utilizing the tools given to them in the statewide voter file system as well as they could,” he said.

In fact, the statewide total of more than 4.4 million registered voters is 93 percent of the estimated number of nearly 4.8 million Indiana adults. That total includes about 385,000 inactive voters.

Rokita said he believed the “extra deadwood” of inactive voters on registration lists left the state more susceptible to voter fraud, particularly though mail-in absentee balloting for which photo identification is not required.

“I’m not at all going as far as saying anything specific is going on that is improper and can be attributed to a certain party or campaign,” he said.

About 750,000 new or updated voter registrations have been made in the state this year, which has seen an active registration effort from the Obama campaign across the state.

Riordan, the Marion County election official, said he believed it was wrong to infer voter fraud was more likely because names had not been purged from the registration rolls. He pointed to the state’s requirement that those voting in person present a government-issued photo ID under a law passed in 2005 by a Republican-controlled Legislature.

“I’m very confident that we are not going to have voter fraud on any real scale — or at all on Election Day here,” Riordan said. “With the photo ID law, I don’t know how you would do it.”